Method of forming dual damascene structure

Abstract

A method of dual damascene structure formation suitable for wiring on semiconductors. The method of forming a dual damascene structure includes the steps of forming an organic dielectric film and a metal oxide film on an inorganic dielectric film, forming a pattern on the resulting multilayer structure, and then etching the structure.

What is claimed is:  
     
         1 . A method of forming a dual damascene structure which comprises the step of superposing an organic dielectric film and a metal oxide film on an inorganic dielectric film.  
     
     
         2 . The metal of forming a dual damascene structure of  claim 1 , wherein the inorganic dielectric film has a mid etch stopper layer therein.  
     
     
         3 . The method of forming a dual damascene structure of  claim 1 , wherein the inorganic dielectric film is a siloxane-based dielectric film having a dielectric constant of from 1.5 to 3.2.  
     
     
         4 . The method of forming a dual damascene structure of  claim 3 , wherein the siloxane-based dielectric film having a dielectric constant of from 1.5 to 3.2 has hydrocarbon groups.  
     
     
         5 . The method of forming a dual damascene structure of  claim 1 , wherein the organic dielectric film comprises an organic polymer having a glass transition point of 400° C. or higher and a heat decomposition temperature of 500° C. or higher.  
     
     
         6 . The method of forming a dual damascene structure of  claim 5 , wherein the organic polymer is selected from the group consisting of polyarylenes, poly(arylene ether)s, polybenzoxazole and polyimides.  
     
     
         7 . The method of forming a dual damascene structure of  claim 1 , wherein the metal oxide film comprises an oxide of at least one metal selected from the group consisting of boron, aluminum, gallium, indium, thallium, silicon, germanium, tin, lead, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, zinc, cadmium, phosphorus, arsenic, antimony, bismuth and cerium.  
     
     
         8 . The method of forming a dual damascene structure of  claim 1 , wherein the metal oxide film has a reflection-preventive function.  
     
     
         9 . The method of forming a dual damascene structure of  claim 1 , wherein the inorganic dielectric film is formed by applying a coating fluid comprising a polysiloxane and an organic solvent, and then heating the coating layer.  
     
     
         10 . The method of forming a dual damascene structure of  claim 1 , wherein the organic dielectric film is formed by applying a coating fluid comprising an organic polymer having a glass transition point of 400° C. or higher and a heat decomposition temperature of 500° C. or higher and an organic solvent, and then heating the coating layer.  
     
     
         11 . The method of forming a dual damascene structure of  claim 1 , wherein the metal oxide film is formed by: applying a coating fluid comprising an organic solvent and a compound obtained by hydrolyzing and condensing an alkoxide of at least one metal selected from the group consisting of boron, aluminum, gallium, indium, thallium, silicon, germanium, tin, lead, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, zinc, cadmium, phosphorus, arsenic, antimony, bismuth and cerium; and then heating the coating layer.  
     
     
         12 . A dual damascene structure formed by the method of  claim 1.